U.S. patent application number 14/452849 was filed with the patent office on 2014-11-27 for expandable prosthetic valve having anchoring appendages.
The applicant listed for this patent is Sorin Group Italia S.r.l.. Invention is credited to Giovanni Righini.
Application Number | 20140350666 14/452849 |
Document ID | / |
Family ID | 41720600 |
Filed Date | 2014-11-27 |
United States Patent
Application |
20140350666 |
Kind Code |
A1 |
Righini; Giovanni |
November 27, 2014 |
EXPANDABLE PROSTHETIC VALVE HAVING ANCHORING APPENDAGES
Abstract
A heart valve prosthesis includes an expandable prosthetic valve
including three valve leaflets coupled to an anchoring structure.
The anchoring structure includes an annular member and a plurality
of arms movably coupled to the annular member at one end. The free
ends of the arms extend radially away from the prosthesis toward a
valve annulus. The arms are configured to fit in a space defined
between an open native valve leaflet and a wall of a valve sinus.
The arms are sufficiently resilient such that they resist downward
movement in response to pressure exerted on the prosthesis,
facilitating anchorage and stabilization of the prosthesis at the
implantation site.
Inventors: |
Righini; Giovanni; (Gland,
CH) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
Sorin Group Italia S.r.l. |
Milano |
|
IT |
|
|
Family ID: |
41720600 |
Appl. No.: |
14/452849 |
Filed: |
August 6, 2014 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
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12639552 |
Dec 16, 2009 |
8834563 |
|
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14452849 |
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61140494 |
Dec 23, 2008 |
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Current U.S.
Class: |
623/2.11 ;
623/2.18 |
Current CPC
Class: |
A61F 2/2418 20130101;
A61F 2220/0058 20130101; A61F 2/2436 20130101; A61F 2/2427
20130101; A61F 2220/0075 20130101; A61F 2230/0054 20130101 |
Class at
Publication: |
623/2.11 ;
623/2.18 |
International
Class: |
A61F 2/24 20060101
A61F002/24 |
Claims
1. A valve prosthesis for implantation in or near a human heart at
a valve site, the valve site including one or more valve sinuses,
the prosthesis comprising: an anchoring structure comprising an
annular outflow member, an annular inflow member, and a plurality
of arms each coupled at one end to the annular outflow member, the
arms having a first end coupled to the annular outflow member and a
second end configured to contact a base of the valve sinus; and a
plurality of leaflets coupled to the anchoring structure and
adapted to substantially allow blood flow in a first direction and
to substantially prevent blood flow in a second direction; wherein
the annular outflow member has an expanded position generally
configured to engage a vessel wall at a location distal to the
valve sinus, and wherein at least one of the plurality of arms is
shaped to engage substantially an entire longitudinally extending
surface of the valve sinus.
2. The valve prosthesis of claim 1 wherein each of the plurality of
arms includes a first leg and a second leg and a U-shaped portion
extending between the first and second legs.
3. The valve prosthesis of claim 1 wherein the arms are configured
to secure and stabilize the prosthetic heart valve at an
implantation site relative to native heart valve leaflets.
4. The valve prosthesis of claim 1 wherein the arms are configured
to contact a space defined between an open valve leaflet and the
sinus wall.
5. The valve prosthesis of claim 1 wherein the arms comprise a
shape memory material.
6. The valve prosthesis of claim 1 wherein the anchoring structure
comprises a shape memory material.
7. The valve prosthesis of claim 1 wherein the arms and said
expandable stent structure are dimensioned so that a native,
stenotic heart valve leaflet can fit therebetween.
8. The valve prosthesis of claim 1 wherein the annular inflow
member is dimensioned to secure the valve prosthesis against a
proximal surface of the valve annulus.
9. A method of implanting an expandable valve prosthesis at a
target implantation site in or near a patient's heart, the
implantation site including at least one valve sinus, the method
comprising: providing a heart valve prosthesis including a
prosthetic valve having three leaflets coupled to an anchoring
structure, the anchoring structure including an annular member
coupled to a plurality of arms having first and second ends, such
that the second ends are not directly coupled to the anchoring
structure; transitioning the prosthesis from an expanded position
to a collapsed position; delivering the prosthesis to a target
implantation site within a patient's heart in a minimally invasive
manner; facilitating expansion of the prosthesis including the
arms; and positioning the second ends of the arms in a space
defined between a native valve leaflet and a sinus wall.
10. The method of claim 9 wherein the step of facilitating
expansion of the prosthesis further includes inflating a balloon
within the prosthesis such that the prosthesis including the arms
is transitioned from the collapsed position to the expanded
position.
11. The method of claim 9 wherein the prosthesis is delivered using
an off pump procedure.
12. The method of claim 9 further comprising positioning an annular
outflow member of the anchoring structure at a location distal to
the valve sinus.
13. The method of claim 9 further comprising expanding the arms
such that the arms contact the wall of the valve sinus along
substantially the entirety of a length of the arms.
14. A valve prosthesis comprising an plurality of valve leaflets
coupled to an anchoring structure, the anchoring structure
including one or more anchoring arms adapted to substantially
engage a valve sinus, the anchoring arms including a free end
adapted to contact a base of the valve sinus adjacent one or more
native valve leaflets.
15. The valve prosthesis of claim 14 further comprising a seal
disposed between a proximal end of the anchoring structure and a
native valve leaflet.
16. A kit for implanting a heart valve prosthesis at an
implantation site within a patient's heart, the kit comprising: an
expandable heart valve prosthesis including an expandable
prosthetic heart valve having three leaflets coupled to an
anchoring structure, the anchoring structure including an annular
outflow member and a plurality of arms movably coupled to the
annular member, wherein the arms are configured to contact a base
of a valve sinus adjacent an open native heart valve leaflet; a
crimping tool adapted to transition the prosthesis from an expanded
position to a collapsed position; and a delivery catheter adapted
to deliver the prosthesis to the implantation site.
17. The kit of claim 16 further comprising an inflatable balloon
adapted to transition the prosthesis from the collapsed position to
the expanded position at the implantation site.
18. The kit of claim 16 in which fingers and said expandable stent
structure are dimensioned so that a native, stenotic heart valve
leaflet can fit therebetween.
Description
CROSS-REFERENCE TO RELATED APPLICATION
[0001] This application is a continuation of U.S. application Ser.
No. 12/639,552, filed Dec. 16, 2009, which claims the benefit of
Provisional Application No. 61/140,494, filed Dec. 23, 2008,
entitled "Expandable Prosthetic Valve Having Anchoring Appendages,"
which is herein incorporated by reference in its entirety.
BACKGROUND
[0002] The present invention relates to cardiac-valve prostheses.
More specifically, the present invention is directed to a
prosthesis amenable to a minimally-invasive implantation procedure
having a stent-like anchoring structure. These prostheses (often
referred to as percutaneous valves) typically include an anchoring
structure, which is able to support and fix the valve prosthesis at
the implantation site, and prosthetic valve elements, generally in
the form of leaflets or flaps, which are connected to the anchoring
structure and configured to regulate blood flow. The prosthetic
valve may be introduced into a position corresponding to the
natural annulus and deployed in situ by divaricating the native
valve leaflets (or following removal of the native leaflets).
SUMMARY
[0003] The present invention, according to one exemplary
embodiment, is a valve prosthesis for implantation in or near a
human heart at a valve site including one or more valve sinuses.
The prosthesis includes an anchoring structure comprising an
annular outflow member, an annular inflow member, and a plurality
of arms each coupled at one end to the annular outflow member, the
arms having a first end coupled to the annular outflow member and a
second end configured to contact a base of the valve sinus. It
further includes a plurality of leaflets coupled to the anchoring
structure and adapted to substantially allow blood flow in a first
direction and to substantially prevent blood flow in a second
direction. The annular outflow member has an expanded position
generally configured to engage a vessel wall at a location distal
to the valve sinus, and at least one of the plurality of arms is
shaped to engage substantially an entire longitudinally extending
surface of the valve sinus.
[0004] According to another embodiment, the present invention is a
valve prosthesis having an plurality of valve leaflets coupled to
an anchoring structure. The anchoring structure includes one or
more anchoring arms adapted to substantially engage a valve sinus.
The anchoring arms include a free end adapted to contact a base of
the valve sinus adjacent one or more native valve leaflets.
[0005] The present invention, according to yet another embodiment,
is a method of implanting an expandable valve prosthesis at a
target implantation site in or near a patient's heart, the
implantation site including at least one valve sinus. The method
includes providing a heart valve prosthesis including a prosthetic
valve having three leaflets coupled to an anchoring structure, the
anchoring structure including an annular member coupled to a
plurality of arms having first and second ends, such that the
second ends are not directly coupled to the anchoring structure;
transitioning the prosthesis from an expanded position to a
collapsed position; delivering the prosthesis to a target
implantation site within a patient's heart in a minimally invasive
manner; facilitating expansion of the prosthesis including the
arms; and positioning the second ends of the arms in a space
defined between a native valve leaflet and a sinus wall.
[0006] According to a further embodiment, the present invention is
a kit for implanting a heart valve prosthesis at an implantation
site within a patient's heart. The kit includes an expandable heart
valve prosthesis including an expandable prosthetic heart valve
having three leaflets coupled to an anchoring structure, the
anchoring structure including an annular outflow member and a
plurality of arms movably coupled to the annular member, wherein
the arms are configured to contact a base of a valve sinus adjacent
an open native heart valve leaflet; a crimping tool adapted to
transition the prosthesis from an expanded position to a collapsed
position; and a delivery catheter adapted to deliver the prosthesis
to the implantation site.
[0007] While multiple embodiments are disclosed, still other
embodiments of the present invention will become apparent to those
skilled in the art from the following detailed description, which
shows and describes illustrative embodiments of the invention.
Accordingly, the drawings and detailed description are to be
regarded as illustrative in nature and not restrictive.
BRIEF DESCRIPTION OF THE DRAWINGS
[0008] FIG. 1 is a sectional view of an aorta of the human heart
having an implanted expandable heart valve prosthesis according to
an embodiment of the present invention implanted within or adjacent
to an aortic valve.
[0009] FIG. 2 is a top perspective view of an expandable prosthetic
valve including an anchoring structure according to an embodiment
of the present invention.
[0010] FIG. 3 is a perspective view of an expandable prosthetic
valve including an anchoring structure according to another
embodiment of the present invention.
[0011] FIG. 4 is a top, schematic view of an expandable prosthetic
valve implanted at an implantation site according to an embodiment
of the present invention.
[0012] FIG. 5 is a flow chart of a method of implanting an
expandable prosthetic heart valve according to various embodiments
of the present invention.
[0013] FIG. 6 is a schematic view of a delivery system for
implanting an expandable prosthetic valve according to various
embodiments of the present invention.
[0014] While the invention is amenable to various modifications and
alternative forms, specific embodiments have been shown by way of
example in the drawings and are described in detail below. The
intention, however, is not to limit the invention to the particular
embodiments described. On the contrary, the invention is intended
to cover all modifications, equivalents, and alternatives falling
within the scope of the invention as defined by the appended
claims.
DETAILED DESCRIPTION
[0015] FIG. 1 shows a perspective view of an expandable prosthetic
valve 2, according to an embodiment of the present invention. As
shown in FIG. 1, the prosthetic valve 2 includes an anchoring
structure 6 having anchoring arms or appendages 10. The prosthetic
valve 2 is shown implanted within or adjacent an aortic annulus 16
of an ascending aorta 18, which is coupled to the left ventricle of
a heart. During normal operation, the left ventricle pumps blood
out of the heart through the aortic annulus 16 and into the
ascending aorta 18 (as indicated by the arrows in FIG. 1). The
prosthetic heart valve 2 is suitable for implantation within or
adjacent a valved intraluminal site using endovascular delivery
techniques known to those of skill in the art. Such a site
includes, for example, the aortic valve 16 (as shown in FIG. 1),
the tricuspid valve, the pulmonary valve, and the mitral valve of a
patient's heart. The prosthetic heart valve 2 is implanted within
the valved intraluminal site such that the native valve leaflets 19
are held in the open position and the prosthetic heart valve 2 is
expanded to bear against a vessel or sinus wall, e.g., the Valsalva
sinus (VS). The prosthetic valve 2, includes an annular proximal
(or inflow) ring 20 located at or near the native valve annulus and
an annular distal (or outflow) ring 21 generally located at an
opposite end of the valve (i.e., away from the valve annulus).
[0016] FIG. 2 is a top perspective view of a prosthetic valve and
FIG. 3 is a side perspective view of a prosthetic valve according
to various embodiments of the present invention. As shown in FIGS.
2 and 3, each of the expandable prosthetic valves 2 includes a
valve sleeve 22 including three leaflets 24a, 24b, and 24c coupled
to the anchoring structure 6. The valve sleeve 22 may be
constructed according to various techniques known in the art. The
valve sleeve 22 includes a base portion 30 with an overall annular
pattern, designed to extend from the lower portion of the
prosthetic valve 2, which at the implantation site, is in a
position proximal to the valve annulus. Three pleat formations 32
extend distally from the base portion 30. The valve leaflets 24a,
24b and 24c extend between adjacent pleat formations 32. Each valve
leaflet 24a, 24b and 24c has a proximal edge with an arched pattern
that extends from the base formation 30 and along two adjacent
pleat formations 32, and a distal edge that extends towards a
central orifice of the prosthesis, so as to cooperate with the
edges of the other valve leaflets in a coapting fashion.
[0017] As is generally known by those of ordinary skill in the art,
in operation, as blood flows out of the ventricle and through the
prosthetic valve 2, the compliant valve leaflets 24a, 24b, 24c are
adapted to deform and move towards the support structure 6 to allow
free flow of the blood through the prosthesis. When the pressure
gradient, and hence the direction of flow, of the blood through the
prosthesis is reversed (i.e., blood is flowing into the left
ventricle), the coapting edges of the valve leaflets 24a, 24b, 24c
move towards each other (e.g., contact each other) such that the
leaflets substantially close and thus prevent the flow of the blood
through the prosthesis 2. In some embodiments of the present
invention, the valve leaflets 24a, 24b, 24c are made in such a way
as to assume, in the absence of external stresses, the closed
configuration. In various embodiments, as shown in FIG. 3 the valve
sleeve 22 includes an annular securing device 36, located at or
near a proximal end of the valve, for securing the prosthetic valve
2 to the valve annulus. According to some embodiments, the annular
securing device 36 is a sewing ring such as that shown and
described in U.S. Pat. No. 5,163,954, which is hereby incorporated
by reference.
[0018] The anchoring structure 6 is adapted to stabilize and secure
the prosthetic valve 2 at an implantation site within a patient's
body. As shown in FIG. 3, the anchoring structure 6 includes an
annular outflow member 52, a plurality of vertical support members
54, and at least three anchoring appendages or arms 10 coupled to
the annular member 52 and adapted to extend radially outward from
the support structure 6. In some embodiments, the arms 10 are
movably coupled to the support structure such that they can
transition from a collapsed position to an extended position. The
annular member 52 and the respective arms 10, together with an
annular inflow ring 20 facilitate anchoring of the prosthetic valve
2 at the desired implantation site. According to some embodiments,
the annular inflow ring 20 is dimensioned to secure the valve
prosthesis against a proximal surface of the valve annulus.
According to some embodiments, the prosthetic valve 2 includes a
seal located at or near the proximal end to prevent perivalvular
leakage. Such a seal is disclosed, for example, in co-pending,
commonly assigned U.S. patent application Ser. No. 11/871,447,
filed Oct. 12, 2007, entitled "Expandable Valve Prosthesis With
Sealing Mechanism," which is hereby incorporated by reference.
[0019] In some embodiments, as discussed in further detail below,
the anchoring structure 6 can include a plurality of anchoring arms
10 made at least partially of shape-memory material (e.g.,
Nitinol), which enable regulation of the anchoring and support
through the control of the memory of the shape-memory material
(e.g., by controlling its temperature). According to other
embodiments, the entire anchoring structure 6 is made from a shape
memory material. In still other embodiments, the anchoring
structure 6 can be made of a re-absorbable material, whereas the
valve sleeve 22 can be constituted by biological and/or synthetic
tissues, which are in part colonizable or re-absorbable.
[0020] During implantation, the prosthetic valve 2 is advanced
towards the implantation site in a radially contracted
configuration, with the annular member 52 in a radially collapsed
configuration. According to some embodiments, the annular member 52
has a collapsed diameter of about 5 to about 15 mm in the collapsed
configuration. Upon delivery to the target implantation site,
expansion of the annular member 52 is facilitated until it reaches
an expanded configuration. According to some embodiments, the
diameter of the annular member 52 ranges from about 18 mm to about
30 mm in the expanded configuration.
[0021] According to some embodiments, the annular member 52 has an
open mesh structure similar to the structure of a stent used for
angioplasty. The mesh structure facilitates expansion of the
annular member 52 from a collapsed configuration to an expanded
configuration similar to the movement of expansion in situ of an
angioplasty stent. According to some embodiments, the annular
member 52 has a rhomboidal-mesh structure. In other embodiments,
the annular member 52 can be fabricated to have any mesh structure
configured to radially expand and collapse in the manner described
above.
[0022] According to some embodiments, the annular member 52 is at
least slightly flared outward like an enlarged opening of the flow
duct of the blood. This configuration may facilitate positive
anchorage of the annular member 52 at the implantation site. In
other embodiments, the annular member 52 flares or curves inwardly,
such as is described for example in commonly assigned, co-pending
U.S. Publication No. 2009/0287296, filed May 13, 2009, entitled
"Atraumatic Prosthetic Heart Valve Prosthesis," which is hereby
incorporated by reference. Securely anchoring the prosthetic valve
2 at the implantation site promotes perivalvar tightness, improving
the hemodynamics and adapting the lines of blood flow in the
ventricular chamber to the flow tube constituted by the valve
sleeve.
[0023] As best shown in FIG. 3, a plurality of vertical support
members 54 are coupled at their proximal ends to the annular member
52. The vertical support members 54 are configured to support the
valve sleeve 22 on the anchoring structure 6. According to some
embodiments, the support members 54 include generally flat bars set
at an angular distance apart from one another by about 120. In some
embodiments, each of the generally flat bars forming the support
member 54 include a plurality of apertures or holes formed therein.
As shown in FIG. 3, each of the pleat formations 32 embraces one of
the support members 54, with the valve leaflets 24a, 24b and 24c
extending in a festoon between two adjacent support members 54. The
generally apertured structure of the support members 54 enables the
valve sleeve 22 to be secured to the support structure 6 by, for
example, suturing stitches according to techniques known to those
of skill in the art. In the case where flaps of polymeric materials
are used, the flaps can be formed directly on the structure, using
techniques such as, for example, dip casting.
[0024] Also coupled to the annular member 52 are a plurality of
anchoring arms 10. As shown in FIGS. 1-4, each of the arms 10
includes first and second legs 60, 62 each having a proximal end 64
and a generally U-shaped portion 66 coupled to and bridging between
the first and second legs 60, 62. The arms 10, in one embodiment,
are coupled to the annular member 52 such that they are disposed
over (e.g., centered with respect to) each of the support members
54. As shown in FIG. 1, according to various embodiments, the
prosthetic valve 2 is sized and shaped such that the annular member
52 is located at or near a distal-most portion of the valve. In
this embodiment, the prosthetic valve 2 has a length such that once
implanted at an appropriate site, the annular member 52 is
positioned distal to the valve sinus (VS), while the annular inflow
member 20 is located at or near the native valve annulus 16.
According to various embodiments, the anchoring arms 10 extend
radially outward a sufficient distance to allow a native, stenotic
valve leaflet to fit between the arm 10 and the corresponding
portion of the body of the anchoring structure 6. As shown, the
arms 10 also extend from the outflow ring 21 at the distal end of
the valve towards the inflow ring 20 at the proximal end of the
valve.
[0025] Additionally, according to some embodiments, each of the
arms 10 is movably coupled to the annular member 52 such that they
are able to transition from a collapsed position suitable for
implantation to an extended position. In the extended position, the
arms 10 are configured to anchor and secure the prosthesis at an
implantation site. In some embodiments, as shown for example in
FIG. 1, the arms 10 extend proximally a sufficient length to engage
the base of the valve sinus (VS), generally at or near the
intersection of the valve sinus and the native valve leaflets 19.
In this configuration, any force applied to the distal end of the
prosthetic valve 2 is transferred by the arms 10 to the base of the
valve sinus. The arms 10, thus operate to generally secure the
prosthetic valve 2 at the implantation site adjacent the valve
annulus and prevent undesired movement or migration of the
valve.
[0026] According to some embodiments, as shown in FIG. 3, the first
and second legs 60, 62 of each arm 10 are made in the form of
struts that extend in a generally sinusoidal fashion, with bends or
open loops situated on either side with respect to an imaginary
line extending approximately in the direction of the overall
cylindrical shape of the prosthesis 2. In other embodiments, the
sinusoidal pattern can be obtained with bends or open loops that
extend from one side and from the other with respect to a line that
extends in a circumferential direction with respect to the
prosthesis. In another embodiment, the first and second legs may
have a mesh structure extending there between. According to some
embodiments, the legs 60 include a bends or loops angled away from
corresponding bends or loops on the legs 62, to provide additional
anchoring within the Valsalva sinus. The bends or loops, for
example, may include a curvature adapted to generally match the
corresponding portion of the interior wall of the Valsalva sinus.
While the embodiments shown in FIGS. 2-4 have three arms 10, the
present invention contemplates embodiments having more or fewer
arms 10. In one embodiment, for example, the anchoring structure 6
includes six arms 10, two arms associated with each of the three
Valsalva sinuses.
[0027] The U-shaped portion 66 extends between and bridges the
first and second legs 60, 62 of each arm 10. According to some
embodiments, the U-shaped portion 66 is integrally formed with each
of the legs 60, 62. According to other embodiments, the U-shaped
portion 66 is a separate piece welded to or otherwise attached to
each of the legs 60, 62 such that it extends between and forms a
bridge between each of the legs 60, 62. According to some
embodiments, the length of the U-shaped portion 66 is selected such
that the legs 60, 62 are configured to press against and inwardly
angled surface of the inner wall of the Valsalva sinus, such that
anchoring is improved.
[0028] The U-shaped portion 66 may be substantially straight,
arched, or otherwise bent at the portion extending between the
first and second legs 60, 62. The U-shaped portion 66 is generally
smooth and free from rough edges such that when it contacts and
presses up against tissue at the implantation site it will not
cause trauma at the site. According to some embodiments, the
U-shaped portion 66 has a curved shape configured to generally
match the contours of the base of the valve sinus. Additionally,
the U-shaped portion 66 may include a sleeve or other protective
coating. The sleeve or protective coating may be formed from a
biocompatible polymer or polymeric coating. According to further
embodiments the sleeve or protective coating may include a
therapeutic agent, such as a steroid, to reduce inflammation at the
implantation site.
[0029] According to some embodiments, as shown for example in FIG.
1, the anchoring arms 10 have an arched or curved configuration,
such that the arms 10 generally follow the longitudinal contours of
the patient's valve sinus wall (i.e., from the start of the valve
sinus near the valve annulus extending distally away from the valve
annulus to the end of the sinus at the vessel wall). In these
embodiments, the anchoring arms 10 substantially conform to or
engage the sinus walls so as to ensure firm anchorage in situ of
the prosthetic valve 2. Examples of arms or support struts
configured to substantially engage the sinus walls are shown in
co-pending, commonly assigned U.S. patent application Ser. No.
11/066,346, filed Feb. 25, 2005, entitled "Minimally-Invasive
Cardiac-Valve Prosthesis" and U.S. patent application Ser. No.
11/352,021, filed Feb. 10, 2006, entitled "Cardiac-Valve
Prosthesis," both of which are hereby incorporated by
reference.
[0030] According to the embodiment shown in FIGS. 1 and 3, the legs
60, 62 of the U-shaped portion 66 define a double curvature. The
first curve, which is convex with respect to a longitudinal
centerline of the valve 2, extends outwardly away from the outflow
ring 21 of the anchoring structure 6. This first curve has a radius
of curvature, R1, selected such that the legs 60, 62 generally
conform to the curvature at the distal portion of the Valsalva
sinus. The second curve, which is concave with respect to a
longitudinal centerline of the valve 2, has a radius of curvature,
R2, selected such that the legs 60, 62 generally conform to the
curvature of the proximal portion of the Valsalva sinus.
[0031] As will be appreciated by those skilled in the art, the
aortic root of the normal heart includes three aortic sinuses,
which are distributed in an approximately angularly uniform way
around the root of the artery distal to the semi-lunar valve (i.e.,
the aortic or pulmonary valve). According to various embodiments,
as illustrated in FIGS. 2-3, the anchoring structure 6 includes
three arms 10 set at an angular distance apart of about 120.degree.
with respect to a longitudinal axis of the prosthetic valve 2.
According to other embodiments, the prosthetic valve 2 includes
more or fewer anchoring arms 10 to match human anatomies includes
more or fewer aortic sinuses.
[0032] According to various embodiments, the anchoring arms 10 are
shaped such that, in the expanded configuration, the arms 10 apply
an outwardly directed radial force against an inner wall of the
Valsalva sinus. In some embodiments, the arms 10 are configured
such that this radial force is selected to sufficiently anchor that
prosthetic valve 10 at the Valsalva sinus under operating
conditions typically present during the human cardiac cycle.
[0033] FIG. 4 is a top cross-sectional view of a prosthetic valve
100 implanted at a native aortic valve site, according to an
embodiment of the invention. As shown, and as discussed in detail
above, the prosthetic valve 100 can be implanted such that the
annular member 152 of the anchoring structure occupies a position
distal to the Valsalva sinuses (VS). According to various
embodiments, the arms 110 can be arranged and positioned relative
to the sinuses of Valsalva such that each of the arms 110 projects
into the respective sinus of Valsalva and substantially engages the
sinus wall. More particularly, as discussed above, the arms 110
project into the Valsalva sinus and rest in a space defined between
an open valve leaflet and the sinus wall. As shown in FIG. 4, each
of the arms 110 can be positioned on opposite sides of the coronary
ostia (CO) in the respective sinuses of Valsalva. The valve
leaflets 24a, 24b, 24c can be positioned within the lumen for blood
flow formed by the annular member 152 with the support members (not
visible) extending into the lumen by a minimal amount. Upon
implantation, the arms 110 of the anchoring structure engage or
bear against the walls of the valve sinus at the implantation site,
without interfering with the blood flow.
[0034] FIG. 5 is a flow chart 200 of a method of implanting an
expandable heart valve prosthesis according to an embodiment of the
present invention. First, a valve prosthesis including an anchoring
structure, is transitioned from an expanded position to a collapsed
position adapted for delivery of the prosthesis to an implantation
site within a patient's heart (block 210). In various embodiments,
the prosthesis is delivered using any of a variety of known
minimally-invasive delivery techniques. According to one
embodiment, the valve is delivered using an off-pump or beating
heart procedure. In some embodiments, a crimping tool or other
similar device known to those of skill in the art, can be used to
radially collapse the prosthetic heart valve including the
anchoring structure. One such crimping system, for example, is
disclosed in co-pending, commonly assigned U.S. patent application
Ser. No. 11/776,695, filed on Jul. 12, 2007, entitled "Expandable
Prosthetic Valve Crimping Device," which is hereby incorporated by
reference. After the prosthesis has been transitioned from an
expanded position to a collapsed position, the prosthesis can be
loaded into a delivery catheter. The prosthesis, according to
various embodiments, is delivered using a valve delivery system of
the type disclosed in U.S. patent application Ser. No. 11/851,523,
entitled "Prosthetic Valve Delivery System Including
Retrograde/Antegrade Approach," and/or U.S. patent application Ser.
No. 11/851,528, entitled "Fluid-Filled Prosthetic Valve Delivery
System," both filed Sep. 7, 2007, both of which are hereby
incorporated by reference.
[0035] The prosthesis is then delivered to a target implantation
site within a patient's heart using known methods and techniques in
a minimally invasive manner (block 220). According to some
embodiments, the delivery catheter is withdrawn facilitating the
automatic expansion of the prosthesis including the support
structure from its collapsed configuration to its expanded
configuration (block 230). According to further embodiments, an
inflatable balloon can be inserted and expanded within the
prosthetic heart valve facilitating expansion of the valve and the
support structure.
[0036] Once expanded, an annular outflow ring of the prosthetic
valve is located generally distal with respect to the valve sinus,
and an annular inflow ring is located generally at or near the
native valve annulus. In embodiments where the arms are fabricated
of a resilient, shape memory material, the arms automatically
expand into position such that they generally engage the walls of
the valve sinus. The arms, according to various embodiments, engage
a space between a native valve leaflet and a sinus wall such that
they anchor and secure the prosthesis at the implantation site. In
this configuration, the arms generally resist downward movement in
response to the pressure exerted upon the prosthesis, such that the
valve remains at the desired implantation site (block 240).
[0037] FIG. 6 is a schematic view of a delivery system 300 for
delivering the prosthetic valve 2 to the desired implant location.
As shown in FIG. 6, the delivery system 300 is being used to
introduce the prosthetic valve 2 in the same direction as the blood
flow, BF. In other words, as shown in FIG. 6, the delivery system
300 is being introduced into to the Valsava sinus (VS) region of
the aortic valve through the left ventricle. As shown, the delivery
system 300 includes a sheath or catheter 302, a first deployment
element 304, and a second deployment element 306. The prosthetic
valve 2 is shown in its collapsed configuration and is disposed
inside the deployment elements 304, 306. As further shown in FIG.
6, in various exemplary embodiments, the delivery system 300
includes a guidewire or stylet 310 coupled to a centering mechanism
314. The centering mechanism 314 may be used to help center the
delivery system 300 in the aorta (AO) during an implantation
procedure. During implantation, the delivery system 300 is used to
advance the prosthetic valve to the desired implant location, for
example, at or near the annulus (A) of the native aortic valve.
Once disposed at the desired location, the implanting physician may
activate the deployment elements 304, 306, by causing one or both
to move back or forth with respect to the prosthetic valve 2, which
thereby releases the valve and allows is to expand radially and
contact the wall of the annulus, aorta, and/or valve sinus.
According to other embodiments, other delivery systems may be used
to implant the prosthetic valve 2. Exemplary delivery systems are
disclosed in U.S. patent application Ser. No. 11/612,974, filed
Dec. 19, 2006, entitled "System for In Situ Positioning of Cardiac
Valve Prostheses Without Occluding Blood Flow," and U.S. patent
application Ser. No. 11/612,980, filed Dec. 19, 2006, entitled
"Instrument and Method for In Situ Deployment of Cardiac Valve
Prostheses," both of which are hereby incorporated by
reference.
[0038] Various modifications and additions can be made to the
exemplary embodiments discussed without departing from the scope of
the present invention. For example, while the embodiments described
above refer to particular features, the scope of this invention
also includes embodiments having different combinations of features
and embodiments that do not include all of the described features.
Accordingly, the scope of the present invention is intended to
embrace all such alternatives, modifications, and variations as
fall within the scope of the claims, together with all equivalents
thereof.
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